Stargate SG-1 S09 E11 The Fourth Horseman (2)

"Saving the world... one episode at a time"

As the Ori plague spreads rapidly, SG-1 hopes that the Prior who caused the disease may hold the key to its cure. Gerak tries to rally the Jaffa to the Ori's cause, prompting Teal'c and Bra'tac to initiate a resistance.